METHOD OF RECEIVING AND PROCESSING DME SIGNALS Russian patent published in 2013 - IPC H04L12/70 

FIELD: radio engineering, communication.

SUBSTANCE: when measuring the position of the front of a video pulse, a DME signal is received and digitised, frequency of the received signal is shifted by an intermediate frequency shift value in the corresponding Nyquist zone and divided by the quadrature by multiplying the digitised signal by the signal of the quadrature generator; the multiplied signal is filtered and decimated by 2, the resultant video signal is transferred to zero frequency; the video signal is filtered; the time position of the front of the video pulse is determined from the level of half the amplitude of the video signal at the intermediate frequency; signals from non-operating Nyquist zones are suppressed by filtration and decimation by 5 and the obtained signal is transferred to the sampling frequency which is equal to 10 MHz; the video signal transferred to the sampling frequency is filtered by a narrow-band low-pass filter; a detection signal is generated by comparing the modulus of the detection pulse from the output of said narrow-band low-pass filter with the video signal, wherein the detection signal allows transmission of the video pulse for subsequent decoding.

EFFECT: improved signal-to-noise ratio at the output of the detector, enabling to obtain stable group delay time when frequency of the input signal changes, preventing distortion of the shape of video pulses by the analogue detector.